Stencil fabric and process of producing the same.



' 30 be cut into the required sizes for use and 55 will not be affectedbythe ink solutions.

NEW YORK, N. 2., ASSIGNOR OF ONE-HALE T6 WY E. WALLACE, OF NEW YORK,11'. Y.

ALBERT n srnirrnn, or

STENCTL FABRIC .ALlD PROCESS OF PRODUCING THE W No Drawing.

T all whom it may concern:

Be it known that I, ALBERT E. STRIPPEL, a citizen of the United States,and resident of the borough of Manhattan, in the city and State of NewYork, have invented a new and useful Improvement in Stencil Fabrics andProcesses of Producing the Same, of which the following is aspecification. The objects of my invention are to pro.- duce a stencilfabric which will be very durable and sufiiciently strong' towithstandthe severe treatment to which it'is'subjected in use; which .willprevent the type for cutting the -steneils from cutting completelythrough the fabric and .blocking out closed characters and which willprovide a clear print. I 1 y The fabric which is most suitable to betreated to render it desirable as a stencil fabric is a long fiberfabric such as is commonly used in this art, as, for instance, Japanesedental paper. 1 This fabric may be used either in a single thiclmess ora multiple thickness as desired and it is pasted along one edge in theusual manner upon a suitable holder of waterproof -material forconvenience in handling the fabric during its treatment. After thefabric hasbeen completed ready for use it may cemented on the usualcardboard or fiber frames. v

The stencil fabric consists of a long fiber fabric provided with ahygroscopic film rendered impervious to the action of the oils containedin printing inks. While this would produce a stencil'fabric which couldbe used for a short time, still to produce a durable stencil it isnecessary to keep this film in a 40 soft and pliable state and also toprotect it from deterioration forotherwise it would be-- come brittleand crack when handled or run through an addressing machine and it wouldalso be subject to decay. This stencil fabric has heretofore beentreated with an organic oil and a preservative as, for instance,glycerin and formaldehyde. The object of this invention is to produce ,astencil fabric which will besuperior to 1-those lieretofore produ ed asto pliability, durability and strength) This result is acj 'complishedjby the use of metallic salts which 5 are perfectly soluble in water andinorganic acidsbut not inorganic oils sothat they 7 Specification ofLetters l'atent.

Application filed July 1, 1913. Serial No. 776,893.

it from the Patented a e. aisle.

This method of preservation by the use of metallic salts has proved tobe much superior to the former preservation method above referred to. 7

Where a solution containing gelatin and bichromate of potash is subected to the presence of light, it has a tendency to thicken, due to thechemical action between the gelatin and the chrome salt whereby thegelatin is rendered insoluble. Heretofore, to keep this solution in agood working degree of fluidity, it has been necesmry to exclude actionof light which makes the process very difficult and expensive. I- havediscovered that by the use of a hydroscopic nitrate, such as sodium nill can expose the solution to the light and yet keep the specificgravity of the solution practically constant for the reason that thenitrate has the effect of materially retarding the setting of the film.The nitrate is not afi'ected by the setting of the film and in thefinished product it aids in keeping the papermoist by drawing moisturefrom the atmosphere along with the chlorid; It also preserves the paperfrom deterioration by the action of microbes which is the only naturalproc- 'ss by which the gelatin and glycerin can be destroyed.

In producing a stencil fabric where the same has to be moistened, beforebeing used, the process is carried outas follows: I dissolve 16 ouncesof a colloid of Wall origin, such as gelatin, in 5 pints of water andheat the same up to' approximately M0" E, and maintain the solution atthis temperature as, for instance, in a water bath. fiould the gelatinhave a tendency to leave an insoluble residue, it is desirable to Swainthe solution. After the elatin has been thoroughly dissolved, I addthereto fi-oin 18 to 22 ounces of glycerin and 1.5 ounces of ahydroscopic nitrate, such as sodium .nih'ate, and mix the partsthoroughly. In a separate vessel I dissolve from .48 of an ounce to .32of an ounce of a chrome salt, such as bichromate of potash, in 5 pintsof water so that the weight of the chrome salt will be between 3%% and3% of the weight of the gelatin. The smaller the percentage of chromesalt, we the softer will be the setfing of the film. This solution isheated to 140 E, and added to the solution of gelafin, glycerin andsodium nitrate. i

The sheet of long fiber fabric to be treated no is run through thesolution and given a thorough saturation. The excess is then removedfrom the fabric by any suitable means, such as rollers and scrapers, oneor both. The sheet is then hung up to dry forabout twenty-four hours.After the drying and setting of the film has taken place, the sheet isplaced upon a suitable non-porous surface, such as glass, and a solutionof glycerin is applied thereto by any suitable means, such as a brush orroller. To this solution of glycerin I may add alcohol and aluminumchlorid. The solution which I have found very suitable is one comprisingsubstantially the following proportions, by weight: water, 16 parts;glycerin, 5 parts; alcohol, 1 part; and aluminum chlorid, 1 part. Thesheet is then again hung up to dry and may thereafter be cut into therequired'sizes for use.

What I claim is 1. The process of producing a stencil fabric whichconsists in treatin a long fiber fabric with 5. solution of a col oid ofanimal origin, glycerin, a hydroscopic nitrate and a chrome salt. 7

2: The process of producing a stencil fabric which consists in treatinga long fiber fabric with a solution of gelatin, glycerin,

sodium nitrate and bichromate of potash.

3. The process of producing a stencil fabric which consists in treatinga long fiber fabric with a solution of gelatin, glycerin, sodium nitrateand bichromate of potash in substantially the following proportions, byweight; gelatin, 16 ounces; glycerin, 18 to 22' ounces; sodium nitrate,1.5 ounces and bichromate of potash, .48 to .32 of an ounce.

4:. The process of producing a stencil fabric which .consists intreating a long fiber fabric, first, with a solution of a colloid ofanimal origin, glycerin, a hydroscopic nitrate and a chrome salt second,drying the fabric; third, applying thereto a solution of glycerin; andfourth, again drying the fab- 5. The process of producing a stencilfabric which consists in treating a long fiber fabric, first, with asolution of a colloid of ammal origin, glycerin, a hydroscopic nitrateand a chrome salt; second, drying the fabric; third, applying thereto asolution of glycerin, alcohol and aluminum chlorid; and

7. The process of producing a stencil fabric which consists in treatinga long fiber fabric, first, with a solution of gelatin, glycerin, sodiumnitrate and bichromate of potash; second, dryin the fabric; third,applying thereto a solution of glycerin; and fourth, again drying thefabric.

8. The process of producing a stencil fabric which consists in treatinga long fiber fabric, first, with a solution of gelatin, glycerin, sodiumnitrate and bichromate of potash; second, drying the fabric; third,applying thereto a solution of glycerimalcohol and aluminum chlorid; andfourth, again dryin the fabric.

e process of producing a stencil fabric which consists in treating along fiber fabric, first, with a solution of gelatin, glycerin, sodiumnitrate .and bichromate of potash; second, drying the fabric; third,applying thereto a solution of glycerin, alcohol and aluminum chlorid insubstantially the following proportions, by weight; glycerin, 5 parts;alcohol, 1 part; aluminum chlorid, 1 part; and fourth, again drying thefabric.

10, The process of producing a stencil fabric which consists in treatinga long fiber fabric, first, with a solution of gelatin, glycerin, sodiumnitrate and bichromate of potash in substantially the followingproportions, by weight; gel'ati'n, 16 ounces; glyc- 1 erin, 18 to 22ounces; sodium nitrate, 1.5

ounces and bichromate of potash, 18 to .32

of an ounce; second, drying the fabric;

third, applying thereto a solution of glycerin; and fourth, again dryingthe fabric.

11. The process of producinga stencil fabric which consists in treatinga long fiber fabric, first, withasolution of gelatin, glycashinsubstantially the following proportions,by weight; gelatin, 16 ounces;glycerin, 18 to 22 ounces; sodium nitrate, 1.5 ounces and bichromate ofpotash, .48 to .32 of an ounce; second, drying the fabric; third,applying thereto a solution of glyc-- erin, alcohol and aluminumchlorid; and

third, applying thereto a solution of glyc-- erin, alcohol and aluminumchlorid in substantially the following proportions, by'

weight; glycerin, 5 parts; alcohol 1 part; alumlnum chlorid, 1 part; andfourth, again drying the fabric.

13. A stencil fabric consisting of a long consists in treating a longfiber 10s erin, sodium nitrate andblchromate of .pot- I fiber fabrictreated with a solution of colloid of animal origin, glycerin, a hydro--scopic nitrate and a chrome salt.

14. A stencil fabric consistin 5 fiber fabric treated with a solutlon ofgelatin, glycerin, sodium nitrate and bichromate of potash.

15.'A lon fiber fabric treated with solutions of co oid of animalorigin, lycerin, 10 a hydroscopic nitrate, 'a chrome sat, alcohol andaluminum chlorid.

16. A'stencil fabric consistinggilof along of a long fiber fabrictreated with solutions of gelatin, glycerin, sodium nitrate, bichromateof potash, alcohol and aluminum chlorid In testimony that I claim theforegomg as my invention, I have signed my name in gresence of twowitnesses,,th1s twenty-slxth ay of June 1913.

- ALBERT E. STRIPPEL.)

Witnesses:

F. GEORGE BARRY, O. S. SUNDGREN.

